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Antibiotics (Basel, Switzerland) May 2024, a foodborne pathogen causing listeriosis, poses substantial societal, economic, and public health challenges due to its resistance, persistence, and biofilm formation...
, a foodborne pathogen causing listeriosis, poses substantial societal, economic, and public health challenges due to its resistance, persistence, and biofilm formation in the food industry. Exploring subinhibitory concentrations of compounds to target virulence inhibition and increase susceptibility to adverse conditions presents a promising strategy to mitigate its impact of and unveils new potential applications. Thus, this study aims to explore the effect of linalool on virulence factors of and potential use in the reduction in its tolerance to stressful conditions. This action was analysed considering the use of two sub-inhibitory concentrations of linalool, 0.312 and 0.625 mg/mL. We found that even with the lowest tested concentrations, a 65% inhibition of violacein production by , 55% inhibition in biofilm formation by and 62% reduction on haemolysis caused by this bacterium were observed. In addition to its impact on virulence factors, linalool diminished the tolerance to osmotic stress (up to 4.3 log reduction after 24 h with 12% NaCl), as well as to high (up to 3.8 log reduction after 15 min at 55 °C) and low temperatures (up to 4.6 log reduction after 84 days with 12% NaCl at 4 °C). Thus, this study paves the way to further investigation into the potential utilization of linalool to mitigate the threat posed by in the field of food safety and public health.
PubMed: 38927141
DOI: 10.3390/antibiotics13060474 -
Pathogens (Basel, Switzerland) May 2024is a human pathogen that has the ability to cause listeriosis, a disease with possible fatal outcomes. The typical route of infection is ingestion of the bacteria with...
High Prevalence of Virulence-Associated Genes and Length Polymorphism in and Genes Identified in Isolates from Meat Products and Meat-Processing Environments in Poland.
is a human pathogen that has the ability to cause listeriosis, a disease with possible fatal outcomes. The typical route of infection is ingestion of the bacteria with contaminated food. In this study, 13 virulence-associated genes were examined with PCR in the genomes of 153 isolates collected from meat products and processing environments in Poland. All isolates possessed genes from LIPI-1-, , , and -as well as four internalins: , , , . Invasion-associated protein , as well as genes and encoding regulatory proteins, were also detected in all isolates. Gene , encoding flagellin, was detected in 113 (74%) isolates. This was the only gene that was not detected in all isolates, as its presence is serotype-dependent. Gene showed polymorphism with longer and shorter variants in PCR amplicons. Two isolates were characterized by truncated genes, lacking 141 bp in their sequence, which was confirmed by gene sequencing. All isolates were positive in hemolysis assays, proving the synthesis of functional PrfA and Hly proteins. Four genotypes of based on polymorphism and two genotypes based on polymorphism were distinguished within the isolates' collection.
PubMed: 38921742
DOI: 10.3390/pathogens13060444 -
Microbiology Resource Announcements Jun 2024is notorious for persistence in food facilities. Phages can significantly impact the ecology of , but there is a dearth of genome sequence data for phages from food...
is notorious for persistence in food facilities. Phages can significantly impact the ecology of , but there is a dearth of genome sequence data for phages from food processing ecosystems. We report the genome sequences of two phages from turkey processing facilities in the USA.
PubMed: 38916304
DOI: 10.1128/mra.00358-24 -
Frontiers in Pharmacology 2024Lung cancer is the most commonly diagnosed and the main cause of cancer death, usually related to cigarette smoking. Furthermore, the microbiota of people exposed to...
INTRODUCTION
Lung cancer is the most commonly diagnosed and the main cause of cancer death, usually related to cigarette smoking. Furthermore, the microbiota of people exposed to cigarette smoke can be modified, making it difficult to eliminate opportunistic microorganisms. The leaves of are a by-product of fruit production and, to date, there have been no studies addressing the antiproliferative, anti-inflammatory, and antimicrobial activities.
OBJECTIVE
Investigate the antimicrobial, Nitric Oxide (NO)-production inhibition, and antiproliferative activities of the essential oil from leaves and its possible effect on the treatment and prevention of damage caused by tobacco.
METHODS
The essential oil (EO) was obtained by hydrodistillation (3 h). Its chemical composition was investigated by GC-MS. It was proposed to investigate antiproliferative activity against human tumor cell lines, namely, breast adenocarcinoma (MCF-7), lung (NCI-H460), cervical (HeLa), and hepatocellular (HepG2) carcinomas. A non-tumor primary culture from pig liver (PLP2) was also tested. The EO capacity to inhibit nitric oxide (NO) production was evaluated by a lipopolysaccharide stimulated murine macrophage cell line. Antibacterial and antifungal activities against opportunistic pathogens were investigated against seven strains of bacteria and eight fungi.
RESULTS
The results indicated the presence of 23 compounds in the essential oil, the majority were spathulenol (45.63%) and β-caryophyllene oxide (12.72%). Leaf EO provided 50% inhibition of nitric oxide production at a concentration of 92.04 µg mL. The EO also demonstrated antiproliferative activity against all human tumor cell lines studied, with GI50 values comprised between 270.86 and 337.25 µg mL. The essential oil showed antimicrobial potential against the bacteria monocytogenes (Murray et al.) Pirie (NCTC 7973) and ATCC 13311 (MIC 1870 µg mL) and fungi ATCC 11730, ATCC 12066, ATCC 90288, var. cyclopium (Westling) Samson, Stolk & Hadlok (food isolate) (MIC 1870 µg mL) and Pers. IAM 5061 (1,400 µg mL).
CONCLUSION
The demonstrated anti-inflammatory, antiproliferative, and antimicrobial activities in the leaves of can add value to the production chain of this plant, being a possible option for preventing and combating cancer, including lung cancer.
PubMed: 38910894
DOI: 10.3389/fphar.2024.1415659 -
IMeta Jun 2024pretreatment mitigated infection in mice. improved gut microbiota disturbed by infection and significantly increased the level of intestinal linoleic acid in mice....
pretreatment mitigated infection in mice. improved gut microbiota disturbed by infection and significantly increased the level of intestinal linoleic acid in mice. Linoleic acid strengthened the intestinal epithelial barrier and reduced pathogen translocation partly by regulating NF-κB/MLCK pathway in a GPR40-dependent manner.
PubMed: 38898984
DOI: 10.1002/imt2.196 -
Applied Microbiology and Biotechnology Jun 2024Bacteriocins have the potential to effectively improve food-borne infections or gastrointestinal diseases and hold promise as viable alternatives to antibiotics. This...
Bacteriocins have the potential to effectively improve food-borne infections or gastrointestinal diseases and hold promise as viable alternatives to antibiotics. This study aimed to explore the antibacterial activity of three bacteriocins (nisin, enterocin Gr17, and plantaricin RX-8) and their ability to attenuate intestinal barrier dysfunction and inflammatory responses induced by Listeria monocytogenes, respectively. Bacteriocins have shown excellent antibacterial activity against L. monocytogenes without causing any cytotoxicity. Bacteriocins inhibited the adhesion and invasion of L. monocytogenes on Caco-2 cells, lactate dehydrogenase (LDH), trans-epithelial electrical resistance (TEER), and cell migration showed that bacteriocin improved the permeability of Caco-2 cells. These results were attributed to the promotion of tight junction proteins (TJP) assembly, specifically zonula occludens-1 (ZO-1), occludin, and claudin-1. Furthermore, bacteriocins could alleviate inflammation by inhibiting the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) pathways and reducing the secretion of interleukin-6 (IL-6), interleukin-1 β (IL-1β) and tumor necrosis factor α (TNF-α). Among three bacteriocins, plantaricin RX-8 showed the best antibacterial activity against L. monocytogenes and the most pronounced protective effect on the intestinal barrier due to its unique structure. Based on our findings, we hypothesized that bacteriocins may inhibit the adhesion and invasion of L. monocytogenes by competing adhesion sites. Moreover, they may further enhance intestinal barrier function by inhibiting the expression of L. monocytogenes virulence factors, increasing the expression of TJP and decreasing the secretion of inflammatory factors. Therefore, bacteriocins will hopefully be an effective alternative to antibiotics, and this study provides valuable insights into food safety concerns. KEY POINTS: • Bacteriocins show excellent antibacterial activity against L. monocytogenes • Bacteriocins improve intestinal barrier damage and inflammatory response • Plantaricin RX-8 has the best protective effect on Caco-2 cells damage.
Topics: Listeria monocytogenes; Bacteriocins; Humans; Caco-2 Cells; Anti-Bacterial Agents; Inflammation; NF-kappa B; Bacterial Adhesion; Tight Junction Proteins; Cytokines; Listeriosis; Cell Movement
PubMed: 38896287
DOI: 10.1007/s00253-024-13228-w -
International Journal of Molecular... May 2024Diarrhoea remains an important public health concern, particularly in developing countries, and has become difficult to treat because of antibacterial resistance. The...
Diarrhoea remains an important public health concern, particularly in developing countries, and has become difficult to treat because of antibacterial resistance. The development of synergistic antimicrobial agents appears to be a promising alternative treatment against diarrhoeic infections. In this study, the combined effect of tetracycline together with either nitroxoline, sanguinarine, or zinc pyrithione (representing various classes of plant-based compounds) was evaluated in vitro against selected diarrhoeic bacteria (, , , , , and ). The chequerboard method in 96-well microtiter plates was used to determine the sum of the fractional inhibitory concentration indices (FICIs). Three independent experiments were performed per combination, each in triplicate. It was observed that the combination of tetracycline with either nitroxoline, sanguinarine, or zinc pyrithione produced synergistic effects against most of the pathogenic bacteria tested, with FICI values ranging from 0.086 to 0.5. Tetracycline-nitroxoline combinations produced the greatest synergistic action against at a FICI value of 0.086. The combinations of the agents tested in this study can thus be used for the development of new anti-diarrhoeic medications. However, studies focusing on their in vivo anti-diarrhoeic activity and safety are required before any consideration for utilization in human medicine.
Topics: Drug Synergism; Tetracycline; Anti-Bacterial Agents; Microbial Sensitivity Tests; Alkaloids; Bacteria; Diarrhea; Humans; Pyridines; Nitroquinolines; Organometallic Compounds
PubMed: 38892226
DOI: 10.3390/ijms25116038 -
International Journal of Molecular... May 2024Flavonoids are an abundant class of naturally occurring compounds with broad biological activities, but their limited abundance in nature restricts their use in...
Flavonoids are an abundant class of naturally occurring compounds with broad biological activities, but their limited abundance in nature restricts their use in medicines and food additives. Here we present the synthesis and determination of the antibacterial and antioxidant activities of twenty-two structurally related flavonoids (five of which are new) by scientifically validated methods. Flavanones (-) had low inhibitory activity against the bacterial growth of MRSA 97-7. However, (C5,7,3',4' = OH) and (C5,7 = OH; C4' = SCH) had excellent bacterial growth inhibitory activity against Gram-negative (MIC = 25 µg/mL for both), while Chloramphenicol (MIC = 25 µg/mL) and (C5,7,3' = OCH; 4' = OH) showed inhibitory activity against Gram-positive (MIC = 25 µg/mL). From the flavone series (-), (C5,7,3',4' = OH), (C5,7,4' = OH; 3' = OCH) and (C5,7,4' = OH) showed good inhibitory activity against Gram-positive MRSA 97-7 (MIC = 50, 12, and 50 µg/mL, respectively), with being more active than the positive control Vancomycin (MIC = 25 µg/mL). (C5,7= OH; 4' = OCH) showed high inhibitory activity against and (MIC = 25 and 15 µg/mL, respectively). These data add significantly to our knowledge of the structural requirements to combat these human pathogens. The positions and number of hydroxyl groups were key to the antibacterial and antioxidant activities.
Topics: Anti-Bacterial Agents; Antioxidants; Flavonoids; Microbial Sensitivity Tests; Escherichia coli; Listeria monocytogenes; Flavanones; Methicillin-Resistant Staphylococcus aureus
PubMed: 38892186
DOI: 10.3390/ijms25115999 -
Animals : An Open Access Journal From... May 2024The inflammasome is a vital part of the host's innate immunity activated by cellular infection or stress. Our previous research identified the bovine SP110c isoform...
The inflammasome is a vital part of the host's innate immunity activated by cellular infection or stress. Our previous research identified the bovine SP110c isoform (bSP110c) as a novel activator of the inflammasome that promoted the secretion of proinflammatory cytokines IL-1β and IL-18 in macrophages infected with or stimulated with lipopolysaccharide (LPS). However, the exact molecular mechanism for inhibiting bSP110c-induced inflammasome activation requires further clarification. Here, the researchers identified bovine DDX3X (bDDX3X) as an NLRP3-associated protein and an inhibitor of the bSP110c-induced inflammasome in the human THP1 macrophage cell line. Immunoprecipitation showed that bDDX3X interacted with the bSP110c CARD domain via its helicase domain. The co-expression of bSP110c and bDDX3X in THP1 macrophages significantly prevented the bSP110c-induced activation of inflammasomes. In addition, both bDDX3X and bSP110c interacted with bovine NLRP3 (bNLRP3), and bDDX3X enhanced the interaction between bSP110c and bNLRP3. The expression of bDDX3X in nigericin-stimulated THP1 macrophages significantly suppressed NLRP3 inflammasome activation, ASC speck formation, and pyroptosis. These findings demonstrate that bDDX3X negatively regulates the bSP110c-mediated inflammatory response by restricting the activation of the NLRP3 inflammasome. This discovery unveils a novel regulatory mechanism involving bDDX3X and bSP110c in coordinating inflammasome activation and subsequent cell-fate decisions in LPS-treated macrophages and, in turn, constitutes a step forward toward the implementation of marker-assisted selection in breeding programs aimed at utilizing cattle's immune defenses.
PubMed: 38891697
DOI: 10.3390/ani14111650 -
Foods (Basel, Switzerland) May 2024() is an opportunistic foodborne pathogen that causes listeriosis in humans and animals, reaching up to 30% case mortality. There are only a few reports in Mexico...
() is an opportunistic foodborne pathogen that causes listeriosis in humans and animals, reaching up to 30% case mortality. There are only a few reports in Mexico about the strains found in various foods. The aim of this study was to determine the prevalence of , serogroups, virulence genes, and antimicrobial resistance in different foods from Reynosa, Tamaulipas, Mexico. strains were characterized by microbiological and molecular methods. Susceptibility to 12 antibiotics was determined according to CLSI and EUCAST. A total of 300 samples of seafood, pasteurized and raw milk, cheese, beef, and chicken were collected from supermarkets and retail markets. The presence of was detected in 5.6% of the samples. Most strains belonged to serogroups 4b, 4d, and 4e (68.4%). All strains presented a minimum of four virulence genes; the most common were , , and (92.1%). A high percentage of antimicrobial susceptibility was observed, with resistance only to STX-TMP (78.9%), STR (26.3%), MEM (21.0%), and E (2.6%). These results show that the foods in Reynosa, Tamaulipas, are a reservoir of and represent a potential health risk.
PubMed: 38890883
DOI: 10.3390/foods13111656